unsettling to the people who work around it. In the past, nuclear power plants have needed workers to cart around the bulky, pinhole camera-like devices to survey rooms one small portion at a time. “But if the room is full of radiation, it’s kind of like a chicken and egg problem—how long do you survey if the surveying is giving you a dose of radiation? Wouldn’t it be great if, instead, you could take an image like infrared for heat?”
It’s possible to have robots operate the large germanium imagers, but H3D points out that in many instances, the areas that need to be checked are only accessible by ladder or are in otherwise prohibitively small spaces that robots can’t access.
H3D’s technology allows people to “see” the type and source of radiation. It can be used in the early detection of leaks, and it can also be used as a tool for cleaning up nuclear accidents and fallout, such as what happened in 2011 in Fukushima, Japan. Its introductory price for universities, national labs, and early adopters is less than $100,000 per device—and it’s small. It weighs just under 9 pounds and is roughly 8 inches long and 5 inches deep.
It also doesn’t require cryogenic cooling the way the germanium-powered devices do (more on that in a minute). It’s air- and water-tight, and Kaye says even if it becomes contaminated, it can be wiped off and decontaminated. H3D prototype devices already have been used to identify failures, verify clean-ups, and locate the primary sources of radiation before routine maintenance will be performed at the Cook Nuclear Power Plant in Bridgman, MI, and at South Korea’s Institute for Basic Science in Daejeon. Recently, several commercial units were sold to nuclear power plants around the U.S., and a few more units are on loan to other nuclear power plants on the condition that H3D receives detailed feedback.
So if the Polaris-H works so well, why doesn’t every nuclear facility in America have one? That turns out to be a complicated story.
Kaye says many have tried to make practical radiation imagers in the past, but they’ve had issues with portability and accuracy. From U-M’s office of technology transfer, where Xconomy interviewed him, Kaye took a dry-erase marker to a whiteboard to illustrate how H3D’s technology works. It hinges on a ¾-inch square block of material called CZT, which stands for cadmium zinc telluride.
CZT is a semiconductor, and Kaye says it has a bad rap in the nuclear industry because its promise has been known but unrealized for almost 40 years. What CZT offers is a compact, room-temperature replacement for germanium, which for decades has been the go-to detector material when users want to precisely record the energy distribution of gamma rays in the environment—information which is then
